Inflatable medical device and related sheath

ABSTRACT

An inflatable balloon is provided. The balloon includes a central lumen open at both ends of the balloon and connected to a gap formed in one sidewall of the balloon. This arrangement may provide the balloon with a generally C-shaped profile with the open central lumen within the balloon along a center axis thereof, such as to allow for perfusion. The balloon may also include an inflation port offset from a central axis and a shaft including an inflation lumen connected to the inflation port. A sheath may also be provided with a window through which the balloon may project in use.

This application claims the benefit of U.S. Provisional PatentApplication Ser. No. 62/096,294, the disclosure of which is incorporatedherein by reference.

INCORPORATION BY REFERENCE

All publications and patent applications mentioned in this specificationare herein incorporated by reference to the same extent as if eachindividual publication or patent application was specifically andindividually indicated to be incorporated by reference.

BACKGROUND

1. Technical Field

Inflatable medical devices, sheaths, and methods for making and usingthe same are disclosed. More narrowly, medical balloons, such as thoseused for dilatation, are disclosed, as is a sheath for use with amedical balloon.

2. Description of Related Art

Inflatable structures, such as balloons, are widely used in medicalprocedures. A balloon is inserted, typically on the end of a catheter,until the balloon reaches the area of interest. Adding pressure to theballoon causes the balloon to inflate. In one variation of use, theballoon creates a space inside the body when the balloon inflates.

Balloons may be used in the heart valves, including during BalloonAortic Valvuloplasty (BAV) and Transcatheter Aortic Valve Implantation(TAVI). The balloons can be used to open a stenosed aortic valve. Astenosed valve may have hard calcific lesions which may tend to tear orpuncture a balloon. Additionally, a precise inflated balloon diametermay be desired for increased safety and control.

The high fluid pressures exerted by the heart, combined with the normalpulsation of the opening and closing valves, pose a very dynamicenvironment for balloon angioplasty. When the balloon is inflated acrossthe valve, the forces tend to squeeze the balloon and create aphenomenon called “ejection,” which causes the balloon to slip out ofthe valve. The clinician then has to deflate the balloon, reposition it,and re-inflate it, which can prolong the procedure. The inability todilate the valve properly can also lead to a failed procedure, and leadto alternate, potentially less desirable treatment regimes.

Accordingly, a need is identified for a device to solve the ejectionproblem. The device would be able to be anchored during inflation, suchthat valve fluctuations do not eject the balloon from the valve. Thedevice would also be adapted to use perfusion to allow blood flowthrough the inflated balloon, which provides the added benefit ofallowing the blood to circulate normally during longer inflation cycles.

SUMMARY

An inflatable medical device is provided that is adapted to useperfusion to allow blood flow through the inflated balloon, whichprovides the added benefit of allowing the blood to circulate normallyduring longer inflation cycles. The device includes a balloon with agenerally C-shaped profile. A corresponding sheath includes a windowthrough which a portion of the balloon may project on inflation. Oncedeflated, the balloon may be rolled onto an associated catheter shaftwith the aid of the sheath.

According to a more specific aspect of the disclosure, an apparatus forperforming a medical procedure in the vasculature includes an inflatableballoon having a generally C-shaped profile providing the balloon withan open central lumen. The balloon includes a convex side and a concaveside having a notch forming a part of the open central lumen. Theproximal end of the balloon includes an inflation port, and a cathetershaft connected to the balloon has a first axis offset from the centrallumen of the balloon.

Reinforcements, such as fibers, may also be wrapped around the balloon.This may include at least one fiber wrapped around the balloon in anaxial direction. At least one fiber may be wrapped around the balloon ina circumferential direction.

The apparatus may also comprise a sheath having a window through which aportion of the balloon may project. The sheath may be connected to afirst outer shaft and the balloon is connected to a second, inner shaftadapted for moving within the first outer shaft, the second, inner shaftincluding an inflation lumen for inflating the balloon. The first outershaft may include a first hub and the second, inner shaft includes asecond hub positioned proximal of the first hub.

A further aspect of the disclosure pertains to an apparatus forperforming a medical procedure in the vasculature. The apparatuscomprises an inflatable balloon and a sheath for at least partiallycovering the balloon. The sheath includes a window through which atleast a portion of the balloon may pass.

In one embodiment, the window extends in a circumferential direction anda longitudinal direction of the sheath. The sheath includes areinforcement adjacent to the window. A corresponding dimension of thewindow in the axial direction is greater than a length of the balloon,which may be generally C-shaped so as to provide the balloon with acentral lumen.

The sheath may be connected to a first outer shaft and the balloonconnected to a second, inner shaft adapted for moving within the firstouter shaft. The second, inner shaft includes an inflation lumen forinflating the balloon. The first outer shaft may include a first hub andthe second, inner shaft has a second hub positioned proximal to thefirst hub.

Still a further aspect of the disclosure pertains to an apparatus forperforming a medical procedure in the vasculature. The apparatuscomprises an inflatable balloon having a central lumen open at both endsof the balloon and connected to a gap formed in one sidewall of theballoon. The balloon may have a substantially C-shaped cross-section.

Yet a further aspect of the disclosure pertains to an apparatus forperforming a medical procedure in the vasculature. The apparatuscomprises an inflatable balloon having a generally C-shaped profileproviding the inflatable balloon with an open central lumen. Theinflatable balloon includes an interior compartment in communicationwith an inflation port. A catheter shaft includes an inflation lumen forcommunicating with the inflation port, the catheter shaft extending atleast partially into an interior compartment of the balloon. Hence, theballoon may be wrapped around the shaft. The balloon may include anupper lobe and a lower lobe, the inflation port being provided in one ofthe upper or lower lobes.

Still another aspect of the disclosure pertains to a method of deployinga medical balloon. The method comprises providing a sheath including awindow, and inflating the balloon through a shaft such that the balloonpasses at least partially through the window of the sheath. The methodmay further include the steps of: (1) deflating the balloon; and (2)wrapping the balloon around the shaft.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

The accompanying drawing figures incorporated herein and forming a partof the specification illustrate several aspects of the adjustablesupport and together with the description serve to explain certainprinciples thereof.

FIG. 1 is an end, view of an inflatable device according to one aspectof the disclosure;

FIG. 2 is a rear view of the inflatable device of FIG. 1;

FIG. 3 is a front view of the inflatable device of FIG. 1;

FIG. 4 is a side view of another embodiment of the inflatable device;

FIG. 5 is a front view of the embodiment of FIG. 4;

FIG. 6 is a side view of another embodiment of the inflatable device;

FIG. 7 is a front view of the embodiment of FIG. 6;

FIG. 8 is a perspective view of the embodiment of FIG. 6;

FIG. 9 is a cutaway top view of a sheath for possible use in connectionwith the inflatable device;

FIG. 10 is a cutaway side view of the sheath;

FIG. 11 is a side view of the inflatable device of FIG. 6 in combinationwith the sheath;

FIG. 12 is a side cross-sectional view illustrating an inflatable deviceprojecting through a window in the sheath;

FIG. 13 is a top cross-sectional view illustrating the rolling up of theinflatable device within the sheath;

FIG. 14 is a partially cutaway, partially cross-sectional view of a hubassembly; and

FIGS. 15-17 are different views of various reinforcements forassociating with the sheath to facilitate retraction of the inflatabledevice.

Reference will now be made in detail to the present preferredembodiments of the aspects of the disclosure, examples of which areillustrated in the accompanying drawing figures.

DETAILED DESCRIPTION

FIGS. 1-3 illustrate one embodiment of an inflatable medical device 10according to the present disclosure. FIG. 1 illustrates an inflatableportion of the device 10, which may be considered as a balloon 12. Inthe illustrated embodiment, the balloon 12 has a length L that issubstantially greater than its width W. Thus, the balloon 12 isconsidered to be elongated as indicated in FIG. 3. However, it ispossible for the balloon 12 to have a shorter length L.

As can be appreciated from FIG. 1, the balloon 12 includes a gap P inone side in communication with a central lumen C. Hence, in thisembodiment, the balloon 12 is considered to be generally C-shaped inprofile, such as when viewed from the longitudinal direction (that is,each cross-section of the balloon along its length is generally C-shapedand substantially identical, without any twisting). Thus, the balloon 12may be considered to have a concave inner surface and a convex outersurface. Alternatively, without deviating from the meaning of the termC-shaped, the balloon 12 may be considered to have two closed ends orlobes (upper and lower) in a single cross-section, with the closed endseither touching each other or opposing to form a gap in fluidcommunication with central lumen C.

For purposes of reducing stress, the balloon 12 may be provided with arelief structure, such as a notch 12 a. The notch 12 a may be along theconcave inner surface of the balloon 12. The arrangement may be suchthat the notch 12 a may partially or fully compress when the balloon 12is in a configuration where the closed ends are touching (compare FIGS.1 and 8).

As also shown in FIGS. 2 and 3, the balloon 12 further includes aninflation port 12 b for receiving an inflation fluid, such as a salinesolution. The port 12 b may be a single port attached to a cathetershaft 14 providing an inflation lumen I for supplying the fluid. As canbe appreciated, the axis of the port 12 b is offset from the centrallumen C, which is generally aligned with a center axis X. In theillustrated embodiment, the port 12 b is connected to a lower lobe ofthe C-shaped balloon 12, but could also be associated with the upperlobe as well, or provided between the upper and lower lobes.

The shaft 14 may be connected to the port 12 b external to the interiorof the balloon 12, and/or may pass through the port 12 b into theballoon interior, including to the distal end thereof. Hence, the shaft14 in this embodiment is offset from the central axis X as well.

The balloon 12 may be manufactured (prior to association with the shaft14) using a vacuum-pressure mold and a parison, or by using watersoluble mandrels (see, e.g., U.S. Patent Application Publication No.20130190796). The balloon 12 may be formed of two C-shaped parts orhalves connected together, or may be formed from an elongated tubularstructure molded into a C-shaped configuration.

As indicated in FIGS. 4-8, one or more reinforcements, such as fibers16, may also be wrapped around the formed balloon 12 to support theintended shape when inflated. For example, as shown in FIGS. 6, 7, and8, circumferential fibers 16 a may be wrapped around the balloon 12 tocollapse the C-shape into an annulus (i.e., the notch 12 a substantiallydisappears, but the balloon 12 remains circumferentially discontinuous),while longitudinal fibers 16 b may be used to retain the shape in theopposite direction. The fibers 16 a, 16 b may be continuous ordiscontinuous, and may be applied in any arrangement as long as theshape-retaining function is provided. The fibers 16 a, 16 b may beinelastic or elastic.

Referring now to FIGS. 9-17, the device 10 may be used in connectionwith an outer sheath 18 for receiving the balloon 12 connected to theshaft 14 (the two structures together could be considered to form asingle device for purposes of this disclosure). The sheath 18 mayinclude a proximal portion 18 a adapted for being attached to a supportshaft 20, and a distal portion 18 b including a window 22. The window 22may be elongated and formed in a sidewall of the sheath, as shown inFIGS. 9 and 10. The sheath 18 may have a closed end at the distalportion 18 b.

The inner diameter of the sheath 18 and shaft 20 is such that theballoon 12 in the deflated condition may be delivered to a position inalignment with the window 22. The window 22 may have a longitudinaldimension D at least as great as the length L of the balloon 12 (seeFIG. 9). The entire length of the sheath 18 is thus greater than thelength of the balloon 12.

In use, the balloon 12 may be positioned in alignment with the window22, and in a configuration where it is folded or wrapped around theshaft 14 extending into the interior compartment of the balloon. Oninflation (and, in the case where it is wrapped, unfurling via rotationof the shaft 14), a portion of the balloon 12 may thus emerge andproject from the window 22 (FIG. 12) in order to provide a treatment inthe vasculature, such as by causing dilatation. Alternatively, theentire balloon 12 may be passed through the window 22 prior toinflation, and then partially or fully inflated. The balloon 12 may bethe C-shaped balloon noted above, or else may take a different form,with a preference for those balloons having perfusion capabilities.

In any case, it can be appreciated, the central lumen C of the balloon12 allows for blood to continue flowing, including along the center axisX, during inflation. In the situation where the balloon 12 remainsassociated with the sheath 18, it can also be appreciated that theopening provided by the window 22 helps to anchor the balloon 12 inposition in order to help prevent undesirable ejection. Continuousperfusion may be provided via the central lumen C despite the full orpartial inflation of the balloon 12 in a C-shaped form, as can beappreciated from FIG. 1.

Upon deflation of the balloon 12, the sheath 18 can also be used toassist in refolding of the balloon 12. Specifically, once deflated, theshaft 14 supporting the balloon 12 may be rotated (FIG. 13), which shaftmay include the inflation lumen I and may pass into the interiorcompartment of the balloon. In view of the offset positioning of theshaft 14, this rotation would tend to urge the balloon 12 against thelip of the distal end portion 18 b of the sheath 18 bounding the window22. This helps to roll the balloon 12 to a wrapped configuration aroundthe shaft 14, such that it may be withdrawn.

In order to facilitate the relative rotation within the outer shaft 20associated with the sheath 18, the inner shaft 14 may be slidablyreceived within an outer hub 20 a, as shown in FIG. 14. The inner shaft14 may also include an inner hub 14 a proximal to the outer hub 20 a,and including the proximal end of the inflation lumen I and guidewirelumen G (if present).

As can be appreciated, the shaft 14 must be able to withstand asignificant amount of torque in order to achieve this rewrapping of theballoon 12. Hence, it is possible to provide the shaft 14 with areinforced configuration, such as by using braiding or hard polymers. Asthis may have a negative impact on trackability, it is possible to usethe device with shorter working lengths with access sites near the heart(e.g., subclavian, jugular, transseptial, etc.). This may reduce theneed for enhanced trackability.

It can be understood that the above-described configuration does notfacilitate the passage of a guidewire through the shaft 14, as would bethe case in a conventional “over-the-wire” configuration. Accordingly,delivery of the device 10 to a treatment site could be achieved throughattachment of a wire external to the shaft 14 or balloon 12, similar tothe situation in a “rapid exchange” configuration. Alternatively, aclinician could thread a wire through the central lumen C of the balloon12, or attach a wire to the external sheath 18.

It can also be understood that the force required to roll the deflatedballoon 12 back inside the sheath 18 may be significant, and couldimpart high stress on the surrounding structure forming the window 22.Accordingly, as shown in FIGS. 15-17, a reinforcement, such as a roundedlip or scroll 22 a, may be provided to help ensure that the window 22does not simply tear during the process. Alternatively or additionally,a reinforcement in the form of a frame 22 b, such as made of a metal orhardened plastic, may be provided along all or a portion of theperimeter of the window 22 in order to provide enhanced strength andtear resistance.

The foregoing has been presented for purposes of illustration anddescription. It is not intended to be exhaustive or, to limit theembodiments to the precise form disclosed. Obvious modifications andvariations are possible in light of the above teachings. All suchmodifications and variations are within the scope of the appended claimswhen interpreted in accordance with the breadth to which they arefairly, legally and equitably entitled. Any elements described herein assingular can be pluralized (i.e., anything described as “orie” can bemore than one), and plural elements can be used individually.Characteristics disclosed of a single variation of an element, thedevice, the methods, or combinations thereof can be used or apply forother variations, for example, dimensions, burst pressures, shapes,materials, or combinations thereof. Any species element of a genuselement can have the characteristics or elements of any other specieselement of that genus. The term “comprising” is not meant to belimiting. The above-described configurations, elements or completeassemblies and methods and their elements for carrying out theinvention, and variations of aspects of the invention can be combinedand modified with each other in any combination.

The invention claimed is:
 1. An apparatus for performing a medicalprocedure in the vasculature, comprising: an inflatable balloon having agenerally C-shaped profile providing the balloon when inflated with anopen lumen along a center axis; and a catheter shaft connected to theballoon, the balloon being wrapped around the shaft in a deflatedcondition.
 2. The apparatus of claim 1, wherein the inflatable balloonincludes a convex side and a concave side having a notch facing the openlumen.
 3. The apparatus of claim 1, the catheter shaft having a centralaxis offset from the open lumen of the inflatable balloon and the centeraxis of the balloon.
 4. The apparatus of claim 1, further includingfibers wrapped around the inflatable balloon.
 5. The apparatus of claim1, further including at least one fiber wrapped around the balloon in anaxial direction and at least one fiber wrapped around the inflatableballoon in a circumferential direction.
 6. The apparatus of claim 1,further including a sheath having a window through which a portion ofthe inflatable balloon may project.
 7. The apparatus of claim 6, whereinthe sheath is connected to a first outer shaft and the catheter shaft isadapted for moving within the first outer shaft, the catheter shaftincluding an inflation lumen for inflating the inflatable balloon. 8.The apparatus of claim 7, wherein the first outer shaft includes a firsthub and the catheter shaft includes a second hub positioned proximal ofthe first hub.
 9. An apparatus for performing a medical procedure in thevasculature, comprising: an inflatable balloon having a generallyC-shaped profile providing the inflatable balloon with an open centrallumen when in an inflated condition, the inflatable balloon including aninterior compartment in communication with an inflation port; and acatheter shaft including an inflation lumen for communicating with theinflation port, the catheter shaft extending at least partially into theinterior compartment of the balloon, whereby the balloon is wrappedaround the shaft when the balloon is in a deflated condition.
 10. Theapparatus of claim 9, wherein the inflatable balloon includes an upperlobe and a lower lobe, the inflation port being provided in one of theupper or lower lobes.
 11. The apparatus of claim 9, wherein the cathetershaft extends at least partially into the interior compartment of theballoon along an offset axis relative to the open central lumen.
 12. Anapparatus for performing a medical procedure in the vasculature,comprising: an inflatable balloon having a generally C-shaped profileproviding the inflatable balloon with an open lumen along a center axisand a port at a proximal end of the balloon in communication with aballoon interior; and a catheter shaft connected to the balloon, theshaft passing through the port into the balloon interior to a distal endof the inflatable balloon.